GCN Circulars
GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.
Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search
To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.
Advanced Search Examples (click to copy):
subject:"Swift"body:"GRB"submitter:"Judith Racusin"5051 results found.
- Trigger 701182: Swift detection of SGR 1935+2154
- More FERMI GBM bursts from the magnetar SGR 1935+2154
- GRB 160521A: 15 GHz detections and upper limit from AMI
- Swift Trigger 690738 is not an astrophysical event
- GRB 160611A: Swift-XRT refined Analysis
- GRB160611.9 MASTER-Net OT detection
- GRB 160607A: Swift-BAT refined analysis
- GRB 160607A: Swift-XRT refined Analysis
- Trigger 689353: Swift detection of a transient near Sgr A*
- GRB 160601A: Swift-XRT refined Analysis
- GRB 160530A: Swift follow-up and X-ray afterglow candidate
- GRB 160525B: Swift-XRT refined Analysis
- GRB 160525B: Nanshan optical upper limit
- GRB 160525A: Swift detection of a probable burst
- Another Swift detection of SGR 1935+2154 (trigger #687124)
- GRB 160519A: Swift detection of a burst
- FACT follow-up of the IceCube event 160427A
- Interplanetary Network Search for IceCube 160427A
- GRB 160509A: MAXI/GSC refined analysis
- GRB 160506A: Swift-XRT refined Analysis
- GRB160504A: Gemini NIR Observations
- GRB 160504A: Swift-XRT refined Analysis
- ICECUBE-160427A : Pan-STARRS imaging and optical transients in the field
- VERITAS rapid follow-up observations of IceCube event 160427A
- GRB 160501A: Swift-XRT refined Analysis
- GRB 160501A MASTER-NET early observations
- GRB 160425A: Skynet PROMPT-CTIO observations of the optical afterglow
- GRB 160325A: Skynet PROMPT-CTIO observations of the optical afterglow
- GRB 160425A: GROND observation
- GRB 160425A: Swift-XRT refined Analysis
- LIGO/Virgo G197392 / LVT151012: Identification of a GW CBC Candidate
- GRB 160424A: Fermi GBM observation
- GRB 160424A: Swift-BAT refined analysis
- GRB 160424A: Swift-XRT observations
- GRB 160424A: Swift detection of a burst
- GRB 160422A: Swift-XRT afterglow detection
- GRB 160419A: Fermi GBM detection
- GRB 160417A: Swift-XRT refined Analysis
- LIGO/Virgo G211117: EWE for NOWT of 12 days follow-up of northern sky
- GRB 160409A found in Swift BAT ground analysis
- GRB 160412A: Swift-XRT refined Analysis
- GRB 160410A: further NOT optical observations
- GRB 160411A: Swift-XRT refined Analysis
- GRB 160410A: MITSuME Akeno optical upper limits
- GRB 160410A: Skynet PROMPT-CTIO observations of the optical afterglow
- GRB 160408A: Swift-XRT refined Analysis
- LIGO/Virgo G211117: LOFAR follow-up
- GRB 160324A: CALET Gamma-Ray Burst Monitor detection
- GRB 160327A: JCMT SCUBA-2 sub-mm observation
- GRB 160327A: Swift-XRT refined Analysis
- GRB 160325A: Swift-XRT refined Analysis
- GRB 160321A: Swift-XRT refined Analysis
- Swift detection of a likely new SGR: SGR 0755-2933
- GRB 160314A: Swift-XRT refined Analysis
- GRB 160314A: Swift detection of a burst
- GRB 160313A: MASTER-Net optical observations
- GRB 160313A: Swift-XRT refined Analysis
- GRB 160310A: Further NOT observations
- GRB 160303A, Swift-BAT refined analysis
- GRB 160303A: Swift-XRT refined Analysis
- Swift possibly triggered on IGR17091-3624
- GRB 160228A: Swift-XRT refined Analysis
- GRB 160227A: Swift-XRT refined Analysis
- GRB 160225B: Fermi GBM detection
- IPN Triangulation of GRB 160225B
- GRB 160225A: MASTER-Amur observations
- GRB 160225A: Xinglong TNT optical observation
- GRB 160225A: Swift-XRT refined Analysis
- GRB 160225A: MITSuME Akeno Optical Observation
- GRB 160225A: MASTER-Amur early observations
- GRB 160223B: MASTER-Amur early observations
- GRB 160223B: Khureltogot optical observations
- GRB 160220B: Further GROND Observations
- GRB 160220A: Swift-XRT refined Analysis
- GRB 160220B: Swift-XRT refined Analysis
- GRB 160216A: Swift-XRT refined Analysis
- LIGO/Virgo G184098: Correction for GCN Circular 18361
- GRB 160206B: Fermi GBM detection
- LIGO/Virgo G211117: LOFAR follow-up
- GRB 160203A: Skynet PROMPT-CTIO observations of the optical afterglow
- GRB 160203A: Swift-XRT refined Analysis
- GRB 160203A: GROND Afterglow Candidate
- GRB 160131A: Swift-XRT refined Analysis
- GRB 160127A: Swift-XRT refined Analysis
- GRB 160123A: Swift-XRT refined Analysis
- GRB 160121A: Swift-XRT refined Analysis
- GRB 160121A: Swift detection of a burst
- GRB 160119A: Swift-XRT refined Analysis
- GRB 160117B: GROND optical/NIR afterglow observations
- GRB 160117B: Swift-XRT refined Analysis
- Konus-Wind observation of GRB 151229B
- IPN Triangulation of GRB 151229B (extremely intense/long)
- GRB 160104A: Continued MITSuME Akeno Optical Observation
- LIGO/Virgo G211117: Subaru Hyper Suprime-Cam follow-up observation
- GRB 160107A: MAXI/GSC detection
- GRB 160104A: Swift-XRT refined Analysis
- GRB 160104A: Fermi GBM observation
- LIGO/Virgo G211117: Summary of Pan-STARRS transients
- GRB 160104A: MASTER early OT detection
- GRB 160104B: MAXI/GSC detection